Claude in Chrome is generally available on every paid plan, with 0% prompt-injection success on Sonnet 5 and Opus 5 under safeguards.

The extension takes autonomous actions (reading, clicking, form-filling) without per-action approval, gated by a safety classifier validating each action plus probes scanning page content for injection attempts. Anthropic publishes per-model attack success rates with safeguards on: 0% for Sonnet 5, Opus 5 and Mythos 5, 0.3% for Fable 5, against 3.8% for Opus 5 with safeguards removed under stronger red-teamed attacks (Anthropic). Enterprise admins can restrict it to an approved domain list. Chrome only, no other Chromium browsers, no mobile. Publishing the safeguards-off number is the part I respect; most vendors publish only the good column.